This invention relates generally to scroll saws which have a saw blade connected between the free ends of the arms of a generally C-shaped or U-shaped member or yoke which reciprocates about a point at the closed end of the yoke to drive the saw blade. More particularly, this invention relates to an apparatus for securing each end of the saw blade to the free ends of the arms of the yoke.
Generally, at least one end of the blade is attached to the free end of an arm by a blade holder and the other end of the blade is secured to the opposite free end of the other arm. Various devices have been used to attach the blade to the free end of the arm. For example, in U.S. Pat. No. 4,503,742 to Sutton, there is disclosed a blade holder which appears to be a simple clamping mechanism for holding the blade in one useful position relative to the moving member. However, the Sutton patent does not appear to provide for a pivotably mounted blade holder of the type that would allow the cutting edge of the blade to remain in proper alignment with a workpiece as the yoke reciprocates. Moreover, the Sutton blade holder only allows for one position of the blade relative to the reciprocating arm.
U.S. Pat. No. 4,841,823 to Brundage discloses a scroll saw holder which allows for two different positions of the blade. The holder can accommodate a front facing blade and a side facing blade. However, the Brundage patent does not appear to disclose a means for allowing the blade holder and blade to pivot during reciprocation of the scroll saw arms especially when the blade is attached in the second position, that is when the blade is at a 90.degree. angle to the reciprocating arm, so as to maintain the optimum position of the cutting edge of the blade relative to a workpiece during operation of the saw with the blade in a 90.degree. position.
U.S. Pat. No. 4,838,138, to Rice et al. describes a scroll saw blade holder and blade aligning device that allows for some pivoting movement of the blade relative to the arms; however, this invention only accommodates one blade position. U.S. Pat. No. 4,807,507, also to Rice et al., discloses a self-lubricating holder for holding a scroll saw blade.
U.S. Pat. No. 4,670,986, to Chen describes a saw blade suspension device for supporting a blade between the arm of a scroll saw. However, the Chen patent allows for the mounting of the blade in one position relative to the reciprocating arms. Furthermore, it is not clear from the Chen patent whether or not the blade holder and blade can pivot relative to the reciprocating arm during use. The Chen patent requires the use of a plurality of parts including a relatively soft main body, a hard pin made of different material, a hardened flat washer, as well as other parts. The Chen device appears to be very complex to assemble and use and even more costly to manufacture.
In FIGS. 7 and 8 of U.S. Pat. No. 2,721,587 to Dremel, there is disclosed a blade holding apparatus for a bench jigsaw having a releasable holding device that allows for the release of blade when it is desired to reciprocate the saw blade transversely of the longitudinal axis of the saw table.
As can be seen from description of the aforementioned prior art scroll saw blade holders, none of the prior art holders adequately address the problems associated with a blade holder in actual use. For example, it is quite useful and convenient to have a saw that allows for the mounting of the blade both in line with a C-shaped arm and also in a 90.degree. angle to the C-shaped arm. Moreover, with a C-shaped arm saw, it is essential to allow the blade to pivot slightly relative to the saw arms in order for the blade to be moved rapidly in a rectilinear path without breaking the blade during the sawing operation. Therefore, it is desirable to have a blade holder apparatus that allows for the proper pivoting of the saw blade when a saw blade is mounted in line with the reciprocating arm or when the saw blade is mounted at 90.degree. to the reciprocating arm. It is also desirable to have a blade holding assembly that allows for the quick release of the blade so that the blade can be conveniently moved from a position in line with the arm to a position 90.degree. to the arm without the use of screwdrivers, pliers, wrenches or other tools. Furthermore, the blade holder assembly should be constructed of a simple design consisting of a minimal number of parts that are easy and economical to manufacture and simple to use.